Question

Osmotic pressure of a solution containing $2g$ dissolved protein per $300{cm}^2$ of solution is $20mm$ of $Hg$ at ${27}^{o}C$. The molecular mass of protein is:

• A. $6239g$ ${mol}^{-1}$
• B. $12315.5g$ ${mol}^{-1}$
• C. $3692.1$ ${mol}^{-1}$
• D. $7368.4g$ ${mol}^{-1}$

Answer 1

The correct option is A $6239g$ ${mol}^{-1}$

$\pi =\frac{n_{B}RT}{V};n_B=\frac{W_B}{M_B}$

$\pi =\frac{W_B}{M_B}\times \frac{RT}{V}$

$M_B=\frac{W_B}{V}\times \frac{RT}{\pi }=\frac{2\times 0.0821\times 300\times 760}{0.3\times 20}$

$=6239.6gmo{l}^{-1}$